JP2012095114A - Communication apparatus and data processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication apparatus and a data processing method for efficiently using a resource and suppressing the deterioration of transmission efficiency.SOLUTION: A communication apparatus 100 performs communication by establishing multiple bearers. A radio link control (RLC) part 170 performs data processing for each bearer and also resetting of the bearers to which resetting is requested, and outputs a resetting announcement to announce the bearers where the resetting is performed to a medium access control (MAC) part 160. The MAC part 160 receives retransmission data of the multiple bearers by performing retransmission control over the multiple bearers, outputs the received retransmission data to the RLC part 170 in order to perform data processing in the RLC part 170, and stops the output of the retransmission data of the bearers announced by the resetting announcement to the RLC part 170 when the resetting announcement is received in the middle of the retransmission control.

Description

  The present invention relates to a communication device and a data processing method, and more particularly, to a communication device and a data processing method for performing a hybrid automatic repeat request (H-ARQ) or an automatic repeat request (ARQ).

  Currently, a 3GPP (3rd Generation Partnership Project) TSG RAN (Technical Specification Group Radio Access Network) is studying LTE (Long Term Evolution) which is a next generation mobile communication system.

  Conventionally, in data communication in LTE, a radio link control layer (Radio Link Control) (hereinafter referred to as “RLC”) in an acknowledged data transfer mode (AcknowledgeMode) (hereinafter referred to as “RLC-AM”), An automatic retransmission request (hereinafter referred to as “ARQ”) method is provided as an error correction function based on a retransmission mechanism of RLC PDU as transmission data (for example, Non-Patent Document 1). In ARQ, a data transmission error is detected by notifying a message (acknowledgment) indicating that the data receiving side has correctly received data to the data transmitting side, and retransmission is performed.

  In addition, a medium access control layer (hereinafter referred to as “MAC”) provides a hybrid automatic retransmission request (hereinafter referred to as “H-ARQ”) method (for example, non-patent). Reference 2). The H-ARQ scheme increases the transmission efficiency of the ARQ scheme, and the data receiving side performs decoding in combination with retransmission data without discarding data in which an error has occurred.

  In LTE, the reliability of data transmission is improved by using these technologies together.

  FIG. 1 is a diagram illustrating a data configuration of an RLC layer and a MAC layer in LTE. In the 3GPP mobile communication system, a virtual connection called a radio bearer (hereinafter referred to as “RB”) is established in a radio section between a communication terminal device such as a mobile device and a base station, Send and receive data. FIG. 1 shows a data configuration when data transmission is performed using two RBs, DRB (Data Radio Bearer) # 1 and DRB # 2.

  In the RLC layer, RLC SDU (RLC Service Data Unit) received from the upper layer is divided or combined into an appropriate size according to the resource size notified from the lower layer. In the RLC layer, an RLC PDU (RLC Protocol Data Unit) with an RLC header (RLC header) added is generated. These processes are performed in units of RBs in the RLC layer. Therefore, ARQ processing performed in the RLC layer is performed independently for each RB.

  On the other hand, at the MAC layer, RLC PDUs of a plurality of RBs notified from the RLC layer are combined and a MAC PDU is added to generate a MAC PDU. The transmission unit of the MAC PDU generated in this way is called TB (Transport Block). In the MAC layer, data of a plurality of RBs are combined and transmitted / received as 1 TB. Accordingly, the H-ARQ process in the MAC layer is performed in units of TB including one or a plurality of RB RLC PDUs.

  In the RLC layer in the LTE scheme, the following functions are provided in order to detect a protocol error in the RLC layer. That is, as shown in the standard of Non-Patent Document 1, in order to detect a protocol error in the RLC layer, the number of retransmissions of RLC PDUs by ARQ is counted. When the number of retransmissions of RLC PDUs by ARQ in the RLC layer reaches the specified upper limit number, it is assumed that a protocol error has occurred, and a signaling connection (RRC (Radio Resource Control) connection) between the communication terminal apparatus and the base station ) Is reset. It tries to recover from the error state by resetting the signaling connection.

  In the recovery method from a protocol error in the conventional LTE method, the RRC connection is reset even when an error occurs in only one RB (for example, DRB # 1 in FIG. 1). For this reason, even if other RBs (for example, DRB # 2 in FIG. 1) are operating normally, data transmission of all RBs is temporarily disconnected and attempts to recover. Therefore, the subject that the communication in RB (for example, DRB # 2 of FIG. 1) which is performing data transmission / reception without problem will be disturbed occurs.

  As a means for solving the above problem, a method of resetting only the RB in which the protocol error has occurred can be considered. However, in this case, the following problems occur.

  FIG. 2 is a sequence diagram for explaining a problem that occurs when a conventional method of resetting only an RB in which a protocol error has occurred is employed.

  From FIG. 2, the RLC PDUs of DRB # 1 and DRB # 2 notified to the RLC unit on the network side are notified to the MAC unit on the network side (step ST1 and step ST2).

  Next, the RLC PDUs of DRB # 1 and DRB # 2 are transmitted from the MAC unit on the network side to the communication terminal apparatus (step ST3). At this time, the MAC unit transmits a MAC PDU that combines these two RLC PDUs of DRB # 1 and DRB # 2 to 1 TB.

  At this time, in step ST1 and step ST2, after transmitting data from the RLC unit to the MAC unit, the RLC unit detects a DRB # 1 protocol error (step ST4).

  In this case, since the MAC PDU transmitted from the RLC unit before the protocol error is detected is transmitted as 1 TB in the MAC unit, if transmission fails, retransmission by H-ARQ is performed in units of 1 TB. (Step ST5). In addition, since the RLC unit process and the MAC unit process operate independently, even if a protocol error is detected in the RLC unit on the network side, retransmission by H-ARQ is continued in the MAC unit. .

  Further, when the RLC unit on the network side detects a DRB # 1 protocol error, the RLC unit notifies the detected error to the RRC unit on the network side (step ST6).

  Next, the RRC unit on the network side notifies the RRC unit on the communication terminal device side of the resetting request (step ST7), and resets DRB # 1 (step ST8).

  Next, the RRC unit on the communication terminal device side makes a reconfiguration request for only DRB # 1 in which a protocol error has occurred to the RLC unit of the communication terminal device (step ST9).

  Next, the RLC unit on the communication terminal device side performs resetting of only DRB # 1 (step ST10).

  Next, after the reconfiguration of DRB # 1 is completed, the RLC unit on the communication terminal device side notifies the completion of reconfiguration of DRB # 1 to the RRC unit on the communication terminal device side (step ST11).

  Next, the RRC unit on the communication terminal device side notifies the completion of reconfiguration of DRB # 1 to the RRC unit on the network side (step ST12).

  During the above processing, since retransmission by H-ARQ in the MAC unit is continued, reception by H-ARQ is performed in the MAC unit after the RLC unit on the communication terminal apparatus side reconfigures DRB # 1. May succeed (step ST13). In this case, the DRB # 1 data transmitted by the network side before resetting is received together with the DRB # 2 data together with the DRB # 2 data (step ST14 and step ST15).

  The receiving side of the RLC unit performs order control based on the sequence number added to the received data. That is, the RLC unit arranges the received data based on the sequence number, assembles the RLC SDU from the RLC PDU, and notifies the higher layer. In addition, the RLC unit resets the sequence number when resetting is performed, and performs control of the order of received data based on the reset sequence number after resetting. Further, the RLC unit cannot distinguish whether the received data is transmitted before resetting or transmitted after resetting.

  Therefore, when the sequence number of the RLC unit is reset by resetting, but the received data is data before the reset of the sequence number, the data order control does not function in the RLC unit, and the RLC unit Assembly from PDU to RLC SDU becomes impossible. As a result, although the receiving side retransmits the data with the missing sequence number by ARQ, the sequence number is shifted between the transmitting side and the receiving side, so that the number of retransmissions finally reaches the specified upper limit number, and again, Reconfiguration occurs due to a protocol error.

  As a means for solving the problem described with reference to FIG. 2, a method disclosed in Patent Document 1 is known.

  FIG. 3 is a sequence diagram showing a method for preventing unnecessary data transmission in Patent Document 1. Note that, in FIG. 3, the same reference numerals are given to the portions that perform the same processing as in FIG. 2, and the description thereof is omitted.

  The RLC unit on the network side resets DRB # 1 (step ST8), and then requests a reset to the MAC unit on the network side (step ST21).

  Next, the MAC unit on the network side stops transmission by H-ARQ.

  As a result, transmission of data of DRB # 2 that is transmitted in the same TB as DRB # 1 and in which no protocol error has occurred is also stopped. Therefore, the RLC unit on the network side retransmits the data of DRB # 2 after resetting (step ST12) (step ST22).

  Thereby, in Patent Document 1, after the reset request, retransmission by H-ARQ in the MAC unit is not performed, so the RLC unit on the communication terminal device side resets the data transmitted before resetting The problem of receiving later is solved.

  In Patent Document 1, although retransmission by H-ARQ is stopped, the corresponding data is retransmitted by an upper layer after completion of reconfiguration, so that data loss is guaranteed.

JP 2003-111147 A

3GPP TS 36.322 V8.7.0 (2009-09) Radio Link Control (RLC) protocol specification (Release 8) 3GPP TS 36.322 V8.7.0 (2009-09) Medium Access Control (MAC) protocol specification (Release 8)

  However, in Patent Document 1, after resetting, DRB data in which no protocol error has occurred is retransmitted (step ST22 in FIG. 3), so that there is a problem that transmission efficiency is lowered.

  An object of the present invention is to provide a communication device and a data processing method capable of efficiently using resources and suppressing a decrease in transmission efficiency.

  The communication apparatus of the present invention is a communication apparatus that establishes a plurality of bearers and performs communication, performs data processing for each bearer, reconfigures the bearer requested to be reconfigured, and performs the reconfiguration. First protocol processing means for notifying the receiver, receiving retransmission data of the plurality of bearers by performing retransmission control across the plurality of bearers, and receiving the received retransmission data for the data processing in the first protocol A second protocol processing unit that outputs to the processing unit and stops the output of the retransmission data of the bearer that has received the notification when the notification is received during the retransmission control. .

  The data processing method of the present invention is a data processing method in a communication device that establishes a plurality of bearers and performs communication, performs data processing for each bearer, resets the bearer requested to be reset, and A first protocol processing step for notifying a bearer to be reconfigured, and receiving retransmission data of the plurality of bearers by performing retransmission control across the plurality of bearers, and receiving the received retransmission data for the data processing Output to the first protocol processing step, and when receiving the notification in the middle of the retransmission control, a second protocol processing step of stopping the output of the retransmission data of the bearer that has received the notification, It was made to have.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to use a resource efficiently, the fall of transmission efficiency can be suppressed.

The figure which shows the data structure of the RLC layer and MAC layer in LTE Sequence diagram for explaining a problem that occurs when a method of resetting only an RB in which a conventional protocol error has occurred is adopted Sequence diagram showing a method for preventing unnecessary data transmission in Patent Document 1 The block diagram which shows the structure of the communication apparatus which concerns on embodiment of this invention The sequence diagram which shows the communication method in the communication system containing the communication apparatus which concerns on this Embodiment

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment)
FIG. 4 is a block diagram showing a configuration of communication apparatus 100 according to the embodiment of the present invention.

  The communication apparatus 100 includes an antenna 101, a radio communication unit 102, an H-ARQ execution unit 103, an RLC PDU decoding unit 104, a notification target RLC PDU determination unit 105, a reset target RB notification unit 106, and a reset The implementation unit 107, the data processing unit 108, and the RRC unit 109 are mainly configured. The communication device 100 is a communication terminal device such as a mobile device.

  The communication control unit 150 includes a MAC unit 160 and an RLC unit 170. The MAC unit 160 includes an H-ARQ implementation unit 103, an RLC PDU decoding unit 104, and a notification target RLC PDU determination unit 105. The RLC unit 170 includes a reset target RB notification unit 106, a reset execution unit 107, and a data processing unit 108.

  The antenna 101 receives a signal and outputs it to the wireless communication unit 102. Further, the antenna 101 transmits a signal input from the wireless communication unit 102.

  The radio communication unit 102 converts the signal input from the antenna 101 from a radio signal to a baseband signal, demodulates it, and outputs it to the H-ARQ execution unit 103. Radio communication section 102 also modulates a transmission signal including a retransmission request input from H-ARQ implementation section 103, converts the frequency from a baseband frequency to a radio frequency, and outputs the result to antenna 101. In addition, the radio communication unit 102 modulates a transmission signal including a message input from the RRC unit 109 via the RLC unit 170 and the MAC unit 160, converts the frequency from a baseband frequency to a radio frequency, and outputs the frequency to the antenna 101. To do. In FIG. 4, the data processing units of the RLC unit 170 and the MAC unit 160 that perform data processing on the message input to the wireless communication unit 102 are omitted for convenience of explanation.

  The H-ARQ execution unit 103 decodes the demodulated signal input from the wireless communication unit 102. Also, the H-ARQ execution unit 103 performs H-ARQ processing across a plurality of RBs, and does not output to the RLC PDU decoding unit 104 when a data reception error is detected. In addition, when the data reception is successful and the data can be acquired, the H-ARQ execution unit 103 outputs the acquired data to the RLC PDU decoding unit 104. Also, the H-ARQ execution unit 103 performs H-ARQ processing across a plurality of RBs, and outputs a retransmission request to the radio communication unit 102 when a data reception error is detected.

  The RLC PDU decoding unit 104 divides the TB unit data input from the H-ARQ implementation unit 103 to obtain decoded data in RLC PDU units. Also, the RLC PDU decoding unit 104 outputs the acquired decoded data to the notification target RLC PDU determination unit 105.

  The notification target RLC PDU determination unit 105 determines the RB data to be notified, and outputs only the data of the corresponding RB to the data processing unit 108. Specifically, the notification target RLC PDU determination unit 105 refers to the reset notification for notifying the reset target RB, which is input from the reset target RB notification unit 106, and the decoding input from the RLC PDU decoding unit 104. It is determined whether to output data to the data processing unit 108. That is, the notification target RLC PDU determination unit 105 does not output the RLC PDU of the RB to be reset to the data processing unit 108, and outputs the RLC PDU of the RB that is not the reset target to the data processing unit 108.

  The reset target RB notification unit 106 receives a notification of the RB to be reset from the reset execution unit 107, and generates a reset notification to notify the RB to be reset. Also, the reset target RB notification unit 106 outputs the generated reset notification to the notification target RLC PDU determination unit 105.

  The resetting execution unit 107 performs resetting in units of RBs. Specifically, when the reset request is input from the RRC unit 109, the resetting execution unit 107 resets the RB requested to be reset. In addition, the resetting execution unit 107 notifies the resetting target RB notification unit 106 of the RB to be reset. Further, the resetting execution unit 107 outputs a resetting completion notification to the RRC unit 109 when the resetting is completed.

  The data processing unit 108 controls the order of data input from the notification target RLC PDU determination unit 105, and performs data processing for generating RLC SDUs.

  The RRC unit 109 outputs a reset request to the reset execution unit 107 when the reset message is included in the control message input from the wireless communication unit 102 via the MAC unit 160 and the RLC unit 170. In addition, when the reconfiguration completion notification is input from the reconfiguration execution unit 107, the RRC unit 109 outputs the reconfiguration completion notification to the wireless communication unit 102 via the RLC unit 170 and the MAC unit 160. In FIG. 4, the data processing units of the RLC unit 170 and the MAC unit 160 that perform data processing on the control message input to the RRC unit 109 are omitted for convenience of explanation. In addition, the RLC unit 170 and the data processing unit of the MAC unit 160 that perform data processing on the resetting completion notification output from the RRC unit 109 are omitted for convenience of explanation.

  Next, a communication method in a communication system including communication apparatus 100 according to the present embodiment will be described using FIG. FIG. 5 is a sequence diagram showing a communication method in a communication system including communication apparatus 100 according to the present embodiment.

  The communication system in the present embodiment is mainly composed of a communication device 100 and a network 200. The network 200 includes a MAC unit 201, an RLC unit 202, and an RRC unit 203. In FIG. 5, parts having the same configuration as in FIG.

  From FIG. 5, the RLC unit 202 on the network 200 side outputs the RLC PDU of DRB # 1 and the RLC PDU of DRB # 2 acquired from the upper layer (not shown) to the MAC unit 201 on the network 200 side (step ST501 and step ST502).

  Next, MAC section 201 transmits DRB # 1 RLC PDU and DRB # 2 RLC PDU to communication apparatus 100 (step ST503). At this time, the MAC unit 201 combines the RLC PDU of DRB # 1 and the RLC PDU of DRB # 2, and transmits a MAC PDU with a MAC header added to 1 TB.

  In step ST501 and step ST502, the RLC unit 202 outputs the RLC PDU of RB # 1 and the RLC PDU of DRB # 2 to the MAC unit 201, and then detects a protocol error of DRB # 1 (step ST504).

  In addition, when transmission of the MAC PDU transmitted in step ST503 fails (in the case of NG), the MAC unit 201 performs retransmission by H-ARQ processing in units of 1 TB (step ST505). At this time, since the processing of the RLC unit 202 and the processing of the MAC unit 201 operate independently, even if a protocol error is detected by the RLC unit 202, the MAC unit 201 continues retransmission by H-ARQ. Is done.

  In addition, when the RLC unit 202 detects a DRB # 1 protocol error, the RLC unit 202 notifies the detected error to the RRC unit 203 on the network 200 side (step ST506).

  Next, RRC section 203 notifies DRC # 1 reconfiguration request to RRC section 109 on communication apparatus 100 side (step ST507).

  Next, RRC section 109 requests reconfiguration of DRB # 1 by notifying RLC section 170 on communication apparatus 100 side of the reconfiguration request (step ST508).

  Next, RLC section 170 resets only DRB # 1 (step ST509).

  Next, RLC section 170 notifies MAC section 160 of resetting to reset DRB # 1 (step ST510).

  In addition, RLC section 202 resets only DRB # 1 (step ST511).

  Next, after the reconfiguration of DRB # 1 is completed, RLC section 170 notifies DRC # 1 of the reconfiguration completion to RRC section 109 (step ST512).

  Next, RRC section 109 notifies RRC section 203 of the completion of resetting DRB # 1 (step ST513).

  Also, the retransmission by the H-ARQ process in step ST505 ends when the MAC PDU is successfully received (step ST514).

  Next, MAC section 160 checks the RB of the received MAC PDU (step ST515).

  Next, when the MAC PDU includes the DRC # 1 RLC PDU, the MAC unit 160 does not output the DRB # 1 RLC PDU to the RLC unit 170, but the DRB # 2 RLC PDU. Only the PDU is output (step ST516).

  As described above, in this embodiment, even if a protocol error occurs in some RBs on the network side, retransmission in TB units including the RB in which the protocol error has occurred continues, so that an RB in which no protocol error has occurred. Retransmission by ARQ can be prevented. Thereby, according to this Embodiment, while being able to use a resource efficiently, the fall of transmission efficiency can be suppressed.

  In this embodiment, the RLC unit notifies the MAC unit of the RB to be reset, so that the MAC unit does not output the retransmission data of the RB in which a protocol error has occurred on the network side to the RLC unit. Thereby, according to the present embodiment, it is possible to suppress a state in which the order control in the RLC unit does not function, and it is possible to suppress resetting due to a second protocol error due to the number of retransmissions reaching the specified upper limit number. .

  In the above embodiment, the MAC unit, the RLC unit, and the RRC unit are provided. However, the present invention is not limited to this, and any protocol that performs the same processing as those other than the MAC unit, the RLC unit, and the RRC unit. Each of the configurations for performing processing can be employed.

  The communication apparatus and data processing method according to the present invention are particularly suitable for implementing a hybrid automatic retransmission request or an automatic retransmission request.

DESCRIPTION OF SYMBOLS 100 Communication apparatus 101 Antenna 102 Radio | wireless communication part 103 H-ARQ implementation part 104 RLC PDU decoding part 105 Notification object RLC PDU determination part 106 Reconfiguration object RB notification part 107 Reconfiguration execution part 108 Data processing part 109 RRC part 150 Communication control part 160 MAC part 170 RLC part

Claims (2)

A communication device that establishes a plurality of bearers and performs communication,
First protocol processing means for performing data processing for each bearer, resetting a bearer requested to be reset, and notifying the bearer to be reset;
By performing retransmission control across the plurality of bearers, the retransmission data of the plurality of bearers is received, the received retransmission data is output to the first protocol processing means for the data processing, and the retransmission control is performed. Second protocol processing means for stopping the output of the retransmission data of the bearer that has received the notification when receiving the notification in the middle of
A communication apparatus comprising: A data processing method in a communication device that establishes a plurality of bearers and performs communication,
A first protocol processing step of performing data processing for each bearer, resetting a bearer requested to be reset, and notifying the bearer to be reset;
By performing retransmission control across the plurality of bearers, the retransmission data of the plurality of bearers is received, and the received retransmission data is output to the first protocol processing step for the data processing, and the retransmission control is performed. A second protocol processing step of stopping the output of the retransmission data of the bearer that has received the notification when receiving the notification in the middle of
A data processing method comprising:

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